「ではなく」 in: 「x」ではなく「y」を使うべきでしょうか？

Question

EDIT: Although very similar, this isn't a duplicate of the thread linked by @binom. The linked thread deals with how 「ではなく」 is formed; this one, with the sense in which 「ではなく」 is used.

I read the following phrase in a Japanese forum, regarding whether to use "something" or "a thing/ things" in English.

自分が何の用事があるか分かっている場合は、「something」ではなく「a thing/ things」を使うべきでしょうか？

In my question title I changed the quoted parts of the sentence to 「x」 and 「y」 respectively, because the focal point of my question isn't about them, but the 「ではなく」 part.

I was wondering if my attempt at translating the sentence is correct?

Shouldn't (you) use "a thing/ things" instead of "something" if (more lit: in the event that) you know (what it is) you're doing?

That's the gist I get from it, despite not having come across 「ではなく」 used in this way. In my (admittedly limited) experience I thought the plain form 「じゃなくて」 would be used within the bulk of the sentence, as polite forms were usually reserved for the end? Furthermore, I expected a 「より...の方がいい」 construction to express preference. Obviously there's more than one way to say something, but this isn't one I've encountered until now.

Much obliged!

Answer 1

「A + ではなく + B」

is an extremely common construct meaning:

"B rather than A", "B over A", "B and not A", etc.

Depending on the context, however, you might also need to consider:

"B instead of A", "B more than A", etc.

as well for the purpose of translation into English.

Looking at your translation, I can say that you clearly got the gist of what the writer is trying to say.

「ではなく」 and 「じゃなくて」 mean the same thing. The only difference is that the former is more formal. 「じゃない」, in general, has been overly popular among Japanese-learners the last couple of decades for some reason, but what many of them do not seem to know is that it sounds very informal/conversational, so they tend to end up using it in situations where it does not fit well.

Finally, you could use a pattern close to 「より...の方{ほう}がいい」 to say just about the same thing as the original sentence. It would be something like:

「自分{じぶん}が何{なん}の用事{ようじ}があるか分{わ}かっている場合{ばあい}は、「something」より「a thing/ things」を使{つか}った方{ほう}がいいでしょうか？」